1. Field of the Invention
The present invention relates to a method of and an apparatus for power generation intended to convert various thermal energies, such as waste heat, into electric energy via chemical reactions.
2. Description of the Prior Art
A reactant reproducible type heat fuel cell has thus far been used as a device for converting thermal energy into electric energy via a chemical reaction without involving the exchange of materials between a power generating apparatus and the outside. This device reproduces the reactants by causing a reaction, reverse to the cellular reaction, to proceed thermally by use of a catalyst. This type of device is, for example, disclosed in Report of the Govt. Industrial Research Inst., Tohoku, Vol. 17, pp. 39-56, (March 1984) by Tamio Ikesyoji. This is shown in FIG. 1.
In FIG. 1, the numerals 10 and 11 represent reactant inlets on the negative electrode side and the positive electrode side, respectively; 12 and 13, product outlets on the negative electrode side and the positive electrode side, respectively; 14, a negative electrode; 15, an electrolyte; 16, a positive electrode; 17, a catalytic reactor; and 18, an external resistor. The symbols A and B signify reactants for a cellular reaction; and C and D, products from the cellular reaction. Hydrazine (N.sub.2 H.sub.4) is exemplified as A, oxygen (O.sub.2) as B, nitrogen (N.sub.2) as C, and water (H.sub.2 O) as D. If hydrogen. (H.sub.2) is used as A, and oxygen (O.sub.2) as B, there is no product corresponding to C, and water (H.sub.2 O) is formed as D. In FIG. 1, a heating means for applying heat energy to be converted into electric power is omitted.
As shown in FIG. 1, the reactant A is introduced from the negative electrode-side reactant inlet 10, and the reactant B is introduced from the positive electrode-side reactant inlet 11, whereafter the products C, D, respectively, are formed. During this process, electrons migrate from the negative electrode 14 to the positive electrode 16, producing electric energy. The resulting products C, D pass the negative electrode-side product outlet 12 and the positive electrode-side product outlet 13, respectively, entering the catalytic reactor 17. There, the products C, D form the reactants A, B by a the reverse reaction to the cellular reaction. The reactants A, B thus reproduced are introduced into the negative electrode-side reactant inlet 10 and the positive electrode-side reactant inlet 11, and used for the cellular reaction again.
This system is advantageous in that electric energy is obtained from heat energy without any materials exchanged between the power generator and the outside.
In the conventional reactant reproducible type heat fuel cell, however, a solid catalyst is used for the catalytic reactor 17. Thus, at low reaction temperatures, even when the reactants A, B are reproduced on the catalyst, they are not easily released. To promote their release, it has been necessary to employ a somewhat high reaction temperature.
This necessity was ascribed to the independence of the fuel cell portion and the catalytic reactor 17 from each other. Because of this independence, the reactants A, B had to be introduced into the negative electrode-side and positive electrode-side reactant inlets 10, 11 after being reproduced in the catalytic reactor 17 and released therefrom.